HM Prison Service has set up a framework agreement with eight contractors to build jails and carry out minor refurbishment works.
The contractors are Wates, Shepherd, AWG, Interserve, Shaylor, Willmott Dixon, Kier and Caledonian Building Systems.

The Prison Service said the appointments had been made on a regional basis and are subject to satisfactory performance and price competitiveness. The maximum term the contractors will have on the framework is 10 years.

Kevin Murray, director of management consultancy Brian Farrington and an adviser to the Prison Service, said the appointments marked the end of a robust competition.

He said: "The effort put into all tenders was evident and the tender evaluation process was exhaustive."

Murray said the smaller number of suppliers chosen to undertake the programme ought to lead to continuous improvement.

The Prison Service is also expected to announce another framework deal, predominantly for refurbishment, in December or January.

Last September, Building revealed how the Prison Service had selected a longlist of consultants to help oversee the refurbishment of the UK's prison stock.

The plan is to spend £3bn on upgrading 137 prisons and to create cell space for an additional 20,000 inmates.

The service has also commissioned Hilary Dalke, a colour consultant from South Bank University, to identify colours that could be used to help with prisoner rehabilitation.